The non-linear pharmacokinetics of prednisone and prednisolone. III. Experiments using the rabbit as an animal model.

Intravenous zero order infusions were administered to New Zealand white rabbits. In a pilot study using one rabbit, prednisone and prednisolone clearance values increased with increase in either prednisone or prednisolone infusion rates. In the second study, prednisone was infused until both prednisone and prednisolone achieved steady-state concentrations. In the third study, prednisone was infused until only prednisone achieved steady-state concentrations. The results of the three experiments support the use of a non-linear reversible metabolism model to describe the pharmacokinetic relationship between prednisone and prednisolone.